In a resin-sealed type semiconductor device using a ceramic substrate, peeling occurs between mold resin and the ceramic substrate. Furthermore, when stress applied from the mold resin to the ceramic substrate is large, there is a concern about long-term reliability. Therefore, various techniques are proposed such as a technique that provides a groove or protrusion in a metal base plate to enhance adhesion to resin and a technique that provides a coating film less harder than mold resin over the entire region of an interface with the mold resin to alleviate stress (e.g., see Patent Literature 1).